• Journal of Food Hygiene and Safety
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• v.26 no.1
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• pp.43-48
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• 2011

For the application of nano-sized material in various fields, the evaluation of nano-sized material toxicity is important. In the present study, various concentrations of 200 nm-sized silicon dioxide nanoparticle suspension were intraperitonially injected into mice to identify the toxicity of silicon dioxide nanoparticle in vivo. In the hematological analysis of group II treated with silicon dioxide nanoparticle 100 mg/kg body weight, lymphocytes and monocytes were significantly different compared to the control group. In group III treated with silicon dioxide nanoparticle 200 mg/kg body weight, lymphocytes, monocytes and hemoglobin were significantly different compared to the control group. In blood biochemical analysis of group III, the concentration of AST, ALT, BUN, and creatinine were significantly different compared to the control group. Histopathologic examination of the kidney indicated a mild injury only in mice received 200 mg/kg silicon dioxide nanoparticle. According to the results of the present study, the significant differences in the hematological and blood biochemical analyses and abnormal histopathological findings in the mouse kidney may have been related to exposure to silicon dioxide nanoparticle.

• Applied Chemistry for Engineering
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• v.21 no.4
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• pp.366-371
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• 2010

Accompanying the rapid advance of nanotechnology, various nano-particles have shown promise as strong antimicrobial agents against a broad spectrum of microorganisms. These nanoparticles also have potential applications in medical devices, water treatments systems, environmental sensors and so on. However, with increasing concerns about the impact of engineered nanoparticles, many researchers are recently reporting the cytotoxicity of nanoparticles. In this review paper, we summarized the antimicrobial activities and mechanisms of various kinds of engineered nanoparticles to imprale understanding about these characteristics of nanoparticles.

• Applied Chemistry for Engineering
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• v.29 no.2
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• pp.138-146
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• 2018

Photodynamic therapy (PDT) is a great potential approach for the localized tumor removal with fewer metastatic potentials and side effects in treating the disease. In the treatment process, a photosensitizer (PS) that absorbs a light energy to generate reactive oxygen is essential. In general, a visible light is used as a light source of PDT, so that side effects from the light source are inevitable. For this reason, upconversion nanoparticles (UCNPs) using near-infrared (NIR) as an excitation source are attracting attention in the field of disease diagnosis and treatment. UCNPs have the low cytotoxicity and phototoxicity, and also advantages such as deep tissue penetration and low background autofluorescence. For PDT, UCNPs should be combined with a PS which absorbs the light energy from UCNPs and transfers it to the surrounding oxygen to produce reactive oxygen. In addition, the therapeutic efficacy can be improved by modifying nanoparticle surfaces, adding anti-cancer drugs, or combining with photothermal therapy (PTT). In this review, we summarize the recent research to improve the efficiency of PDT using UCNPs.

• Proceedings of the Korea Society of Environmental Toocicology Conference
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• 2006.05a
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• pp.92-93
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• 2006

• Journal of the Korean Magnetics Society
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• v.16 no.1
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• pp.66-70
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• 2006

Magnetite nanoparticles, which have been extensively used in many fields, were encapsulated with a natural polymer, chitosan, to improve their biocompatibility. We have synthesized magnetite $(Fe_3C_4)$ nanoparticles using chemical coprecipitation technique with sodium oleate as surfactant. Nanoparticle size can be varied from 1.2 to 7.4nm by controlling the sodium oleate concentration. Magnetite phase nanoparticles could be observed from X-ray diffraction. Magnetic colloid suspensions containing particles with sodium oleate and chitosan have been prepared. High magnetic property chitosan-microsphere particles were prepared from oleate-coated magnetite suspension using spray method. The surftce, and tile morphology of the magnetic chitosan microsphere particles were characterized using optical microscope and scanning electron microscope. Magnetic hysteresis measurement were performed using a superconducting quantum interference device (SQUID) magnetometer at room temperature to investigate the magnetic properties of the chitosan microspheres including magnetite nanoparticles. The SQUID measurements revealed superparamagnetism of nanoparticles.

• Journal of the Microelectronics and Packaging Society
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• v.26 no.1
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• pp.23-28
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• 2019

The Titanium oxide ($TiO_2$) is an attractive ceramic material which shows non-toxic, high refractive index, catalytic activity and biocompatibility, and can be fabricated at a low cost due to its high chemical stability and large anisotropy. $TiO_2$ nanoparticles have been prepared by sol-gel method. The pH of solution can affect the $TiO_2$ crystallinity during the formation of nanoparticles. The prepared nanoparticles were characterized using Fourier transform infrared spectroscopy, scanning electron microscopy, X-ray diffraction, photoluminescence spectroscopy in order to investigate their structural and photoluminescence properties. Through these analysis, the size of $TiO_2$ nanoparticles were found to be smaller than 5 nm. As the crystallinity of the nanoparticles increased, the emission of PL in the 550 nm region increased. Therefore, luminescence characteristics can be improved by controlling the crystallinity of the $TiO_2$ nanoparticles.

• Bulletin of Food Technology
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• v.24 no.3
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• pp.308-324
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• 2011

나노기술을 식품에 응용하게 되면 영양소의 전달, 식품의 색, 향미, 물성 등이 향상되고 식품 포장재나 분석에 응용하는 경우 저장성 증진이나 시료 전처리 효율 및 기기 감도를 증가시키는 것으로 알려지고 있다. 이러한 장점으로 인해 유기 및 무기 나노입자, 나노섬유, 나노에멀전, 나노크레이 등의 나노물질을 식품첨가물, 건강기능소재, 식품 접촉물질 등으로 응용하는 시도가 식품산업계에서 급속히 확산되고 있다. 나노물질의 사용범위가 다양해질수록 나노물질의 환경 및 인체 노출가능성은 높아지게 된다. 그러나 아직 나노물질의 독성 및 위해성에 대해서는 초기 단계 수준의 연구가 진행되고 있는 정도이다. 또한 나노기술의 위험 평가에 대한 신뢰성이 제고될 수 있도록 나노물질에 대한 유해성 자료의 생산뿐만 아니라 나노물질의 물리화학적 특성과 노출량을 측정할 수 있는 적절한 측정수단이 확립되어야 한다. 나아가 식품에 나노기술의 적용으로 인한 이익은 최대화하고 부작용은 최소화하여 소비자의 건강을 보호하기 위해 식품나노물질의 생산, 가공, 유통, 소비, 폐기 등에 관한 전 생애(lifecycle) 평가 및 관리가 이루어지도록 적절한 제도적 장치가 마련되어야 한다.

• Journal of Korean Society of Environmental Engineers
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• v.34 no.12
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• pp.855-862
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• 2012

Caenorhabditis elegans, a free-living nematode mainly found in the soil pore water, roles the critical function in trophic levels, energy flow, and decomposition in soil ecosystem. C. elegans is commonly used species to test soil toxicity. Recently, they are employed broadly as a test organism in nanotoxicology. In this study, a review of the toxicity of nanomaterials for C. elegans was presented based on SCI (E) papers. The nanotoxicity studies using C. elegans have been reported in 20 instances including the mechanism of toxicity. Most studies used K-medium, S-medium, and NGM (Nematode Growth Medium) plate as an exposure medium to test toxicity of nanoparticles. The effects observed include anti aging, phototoxicity, genotoxicity, and dermal effects on C. elegans exposed to nanoparticles. We found that the toxic mechanisms were related with various aspects such as lifespan abnormality, oxidative stress, distribution of particles on inter-organisms, and stress-related gene analysis. C. elegans has advantage to test toxicity of nanoparticles due to various cellular activities, full genome information, and easy observation of transparent body. C. elegans was considered to be a good test species to evaluate the nanotoxicity.

• Clean Technology
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• v.13 no.3
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• pp.161-172
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• 2007

Fusion technology based on the nanotechnology should be introduced to clean technology for the breakthrough advances. Today, nanoparticles, nanotubes and other engineered nanomaterials are already in use in hundreds of everyday consumer products, and these materials are able to move around the human and environmental mediamore readily than larger particles of pollution. Because of their extremely small size and large surface area, nanoparticles are known to be more reactive and toxic than larger particles. Consequently, this feature raised many concerns of significant health, safety and environment. Herein, we reviewed risk assessment for health and environmental hazards of nanomaterials, and then revealed the potential hazardous of nanomaterials.

• Journal of Convergence for Information Technology
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• v.8 no.5
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• pp.45-50
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• 2018

The functional nanomaterials of fluorescent dye-doped silica nanoparticles(NPs) are applied to bio applications such as bio-labeling of DNA micro-array, and bio-imaging. Organic dye-doped fluorescent silica NPs exhibit excellent bio-compatibility, non-toxic, and highly hydrophilic properties. In this study, organic fluorescent dyes were dissolved in ethanol, and deionized(DI) water. Organic fluorescent dyes were physically adsorbed to silica NPs and chemically doped to silica NPs. The fluorescence characteristics(FLC) was investigated by UV lamp irradiation of 365 nm wavelength. As results, the FLC of dye-doped silica NPs exhibits better than dye-adsorbed silica NPs and the FLC was improved with the increase of concentration of doped-dyes. The fluorescent organic dyes were well dissolved in ethanol than DI water. The photostability of dye-doped silica NPs was superior than pure fluorescent organic dye. The FLC of optimized dye-doped silica NPs would be applied to agent of non-invasive fluorescence bio-imaging in live cell and in vivo.